| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.18 122/158] tpm/tpm_i2c_infineon: switch to i2c_lock_bus(..., I2C_LOCK_SEGMENT) | Date | Tue, 18 Sep 2018 00:42:32 +0200 |
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4.18-stable review patch. If anyone has any objections, please let me know.
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From: Peter Rosin <peda@axentia.se>
[ Upstream commit bb853aac2c478ce78116128263801189408ad2a8 ]
Locking the root adapter for __i2c_transfer will deadlock if the device sits behind a mux-locked I2C mux. Switch to the finer-grained i2c_lock_bus with the I2C_LOCK_SEGMENT flag. If the device does not sit behind a mux-locked mux, the two locking variants are equivalent.
Signed-off-by: Peter Rosin <peda@axentia.se> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Tested-by: Alexander Steffen <Alexander.Steffen@infineon.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/char/tpm/tpm_i2c_infineon.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
--- a/drivers/char/tpm/tpm_i2c_infineon.c +++ b/drivers/char/tpm/tpm_i2c_infineon.c @@ -117,7 +117,7 @@ static int iic_tpm_read(u8 addr, u8 *buf /* Lock the adapter for the duration of the whole sequence. */ if (!tpm_dev.client->adapter->algo->master_xfer) return -EOPNOTSUPP; - i2c_lock_adapter(tpm_dev.client->adapter); + i2c_lock_bus(tpm_dev.client->adapter, I2C_LOCK_SEGMENT); if (tpm_dev.chip_type == SLB9645) { /* use a combined read for newer chips @@ -192,7 +192,7 @@ static int iic_tpm_read(u8 addr, u8 *buf } out: - i2c_unlock_adapter(tpm_dev.client->adapter); + i2c_unlock_bus(tpm_dev.client->adapter, I2C_LOCK_SEGMENT); /* take care of 'guard time' */ usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI); @@ -224,7 +224,7 @@ static int iic_tpm_write_generic(u8 addr if (!tpm_dev.client->adapter->algo->master_xfer) return -EOPNOTSUPP; - i2c_lock_adapter(tpm_dev.client->adapter); + i2c_lock_bus(tpm_dev.client->adapter, I2C_LOCK_SEGMENT); /* prepend the 'register address' to the buffer */ tpm_dev.buf[0] = addr; @@ -243,7 +243,7 @@ static int iic_tpm_write_generic(u8 addr usleep_range(sleep_low, sleep_hi); } - i2c_unlock_adapter(tpm_dev.client->adapter); + i2c_unlock_bus(tpm_dev.client->adapter, I2C_LOCK_SEGMENT); /* take care of 'guard time' */ usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI);
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